The dispute involves up to 7,000 classroom assistants and has been dragging on for over 10 years. It centres on salaries and pay grades. Most special schools are expected to be closed by the strike and many other schools are likely to have to send pupils home at lunchtime.

John Corey, General Secretary of NIPSA, the main union involved, said the dispute would show the anger of the assistants, who are all women, at the shameful way they had been treated and that they were determined to win fair pay.

He said the employers had known for months about the possibility of a strike and then they had come in with too little, too late. Last night talks were held at Stormont between representatives of four unions and the five education boards who are the employers.

They ended with both sides appearing optimistic about a possible settlement that would avert a planned follow-on strike next week. The Stormont Education Minister, Caitriona Ruane, said yesterday she was convinced the dispute could be resolved through dialogue.

This will be one of the first tests on the industrial front for the new Northern Executive.